The G.I. Joe: The Rise of Cobra star told Details magazine that he was rushed to hospital with severe burns to his privates after the on-set mishap.
Boiling water was accidentally poured down Tatum's wetsuit to stop him from getting hypothermia while shooting The Eagle of The Ninth in the freezing waters off Scotland.
Stagehands reportedly forgot to dilute the boiling water, straight from the kettle, with cold water.
The 29-year-old told Details it was "the most painful thing I have ever experienced in my life".
"I was trying to pull the suit away from my body to somehow get away from the boiling water, and the more I pulled the suit away, the lower the water went. It just went straight down," he said.
"I've been to the hospital, gotten stitches, had broken fingers and toes. But this was a suffocating kind of pain."
Tatum reportedly told his driver he may have to be knocked unconscious because the pain was so unbearable.
After reaching the hospital - an hour away - a team of doctors salvaged and bandaged the wound.
"I had five guys looking at my shriveled, burned penis," Tatum said of his hospital visit.
For anyone wondering how the recovery went, Tatum was happy to report he is fully recovered.
"I'm good . . . now," he said.
"Now my penis is fantastic! One hundred percent recovered. Put me back in the game, Coach."